Mercedes Lynn Reid
by Arisa Coulson-Rogers
Summary: Spencer has a twin sister, Mercedes "Mercy" Lynn Reid. Mercy's also a genius with an IQ of 197. She gets stabbed nearly to death by the Boston Reaper while attending Harvard, causing her to meet and eventually fall in love with Hotch. Hotch/OC. Don't like it, don't read it.
1. the begining

Disclaimer: I don't own Hotch or Criminal Minds, though I wish I did (especially Hotch). The name Mercedes came from a book series that I'm currently reading By Patricia Briggs, and Lynn is a shortening of my own middle name Katlyn.

* * *

The first thing I can remember clearly is playing baseball with Spencer and a bunch of neighborhood boys. We were on a little league team that our father couched; I was the only girl on the team and the best player. Spencer didn't like playing and wasn't very good at it.

We overheard some of the parents talking nearby. "I've never seen a set of twins so different. They're both extremely smart, but Mercedes is so athletic and Spencer is so clumsy he can barely function." One of the mothers said. Spencer looked down ashamed. I was up to bat, when I got to the plate I gripped the bat hard in anger. I hit the ball directly at the tree next to the woman who put Spencer down, the ball hit the tree hard and the woman screamed. Dad grounded me for two weeks.

*** Criminal Minds***

When the two weeks were up Spencer and I went to the park across the street to play chess. We almost always played with adults, so when a man came up to us and asked if he could play we didn't think anything of it. We played for awhile and the man talked to Spencer, only to Spencer. The man's voice was a color I didn't like. "We need to get home for dinner." I said. I didn't wait for the man's response, I grabbed Spencer's arm and pulled him away. We walked quickly home, I told Mom as soon as we got in the door. "I didn't like him Mom. His voice was a bad color." I said. Mom nodded, she always trusted my bizarre explanations of things.

We moved a week later. Spencer and I were 4.

*** Criminal Minds***

Dad took me to several doctors over the years because he thought something was wrong with me because my senses were extremely strong and I see colors when I hear sounds. The last doctor took a scan of my brain. "The part of her brain that processes senses is very enlarged. That with the symptoms you both described leads me to believe that Mercedes has a condition called Synesthesia. Where her senses are, in a way, crossed." The doctor said.

"How do we fix it?" Dad asked. The doctor made a face.

"There's nothing to fix, Mr. Reid. There's nothing wrong with your daughter, her brain just works differently than ours." He said. I was 8.

*** Criminal Minds***

Spencer and I were standing in the hallway, mom and dad were arguing again. Spencer grabbed my hand and I could tell from the way he was trembling that he was crying. I squeezed his hand and he leaned his curly head on my shoulder. Then I heard the front door open and I let go of Spencer's hand and ran out towards the door. My dad was in the doorway holding a suitcase. "Dad!" I called out. He turned to look at me.

"Mercedes, take care of your brother." He said and then he was gone. Spencer and I were 10 and sophomores in high school.

***Criminal Minds***

We were 12 when we graduated high school. Spencer and I got scholarships to Caltech. Where Spencer got PhDs in Mathematics and Engineering and I got PhDs in Behavioral and Social Neuroscience and Engineering. From there, I go to Harvard and study Psychology. Spencer goes to Yale and studies Psychology, Sociology, and Chemistry.

* * *

A/N: This chapter is the back story, the rest will have less time jumps. Also, Synesthesia is a real condition that is a bit different for everyone who has it. Please feel free to Google the specifics like I did.


	2. Boston Reaper part 1

***September 2, 1998***

It was my second year at Harvard and I almost had my undergraduate degree because I took so many classes. My roommate, Rayne, teased me about being a Goth egghead that needed a social life. So she was surprised when I said I was going to Boston for a Green Day concert. "You're what?" Rayne asked. I stepped out from behind my vanity screen dressed in my favorite Green Day t-shirt, a pair of black skinny jeans with holes in them, and black socks.

"Going to the concert in Boston." I said sitting on the bed to pull on my dark green Converse high-tops.

"Who are you and what have you done with my study obsessed roommate?" She asked sarcastically. I finished tying both shoes.

"Just because some of us actually study doesn't mean we're obsessed with it, Ray." I said. I stood up and grabbed my black leather jacket and my messenger bag that was covered with various band buttons. "You keep saying I need a social life, so I'm going to a concert. And, no, you can't come."

"Why? Are you going with a boy there?" She asked with an evil smirk.

"I only have one ticket, dumbass." I said deadpan.

"So you're meeting him there?" She asked.

"I'm not meeting a guy, Ray, or a girl. I'm not attracted to anything, you should know that by now." I said.

"Geez, I was messing with you Mercy. Learn to take a joke." She said.

"Learn to not be so boy obsessed." I said. I opened the door to our dorm room and one of her many boyfriends was standing there with his hand raised like he was about to knock. I turned back to Rayne. "If he's still here by the time I get back, he's getting pepper sprayed." I shoved past the gaping boy and walked down the hall.

Out in the parking lot I walked to my black bug and climb in the driver's seat. I check my make-up in the mirror on the visor. The green eye-shadow, black eyeliner and mascara made my blue eyes pop. I pushed my chocolate brown wavy hair behind my ear and started the car. I pulled out of the parking lot.

I got off the freeway in Boston and turned onto an empty street. About half way down the street, something hit my windshield and left a large crack across it. I slammed on the brakes. "Damn." I muttered and pulled off to the side of the road. I pulled out my cell phone and started to dial the tow truck company when a dark car pulled up behind me. Something about it didn't fell right so I called 911 instead.

When the driver of the car behind me got out I could see in my rearview mirror he was wearing dark mask. I dropped my phone on the seat next to my leg and grabbed my pepper spray. "911, what's your emergency?" I heard just before the man in the mask shot out my window. I screamed and tried to pepper spray him. He slashed my arm with a knife and I lost my grip on the can and it clattered to the floor of the car. He tried to stab me in the chest and I fought him. My arms and hands were shredded.

He opened the door and I tried to climb across the seat to the passenger's side of the car, knocking my phone to the floor. I ended up sprawled across the seat and he climbed in on top of me. I reached and found a text book on the floor; I picked it up and hit him in the side of the head with it. It stunned him for a second and I tried to hit him again. He caught my arm right before I hit him a second time. "Little bitch." He snarled, his voice was the darkest black I'd ever seen. He knocked the book into the back seat.

He plunged the knife into the right side of my chest and I yelped in pain. He stabbed me over and over and over again and I finally blacked out.

I came too at the sound of sirens. It was hard to breath and I couldn't get my eyes open. I heard footsteps and cringed. "Hey, she's still alive!" A smooth, deep male voice called, it was a nice shade of gold. "Miss, can you hear me?" I finally pried my eyes open. I looked up into soft brown eyes. "Just hang on. My name is Agent Aaron Hotchner and I'm with the FBI. You're safe." He said and tucked my hair behind my ear. I managed to grab his hand and he squeezed very gently. "Hurry up!" He yelled over his shoulder. "Can you tell me your name, sweetheart?" He asked me.

"M-" I got out before I started coughing up blood.

"Easy." He said. "Breathe." I took a few shallow breaths. "There we go." I could hear other people around us now.

"I'm…" I paused to breath. "Mercy." My eyes started to flutter.

"Stay with me, Mercy. Keep those beautiful eyes of yours open." He said. "We're gonna get you to the hospital real soon."


	3. 58 times

The ambulance ride is a blur. **He** is the only thing I remember. "Keep breathing, Mercy." He said. I kept my eyes open by looking into his, their dark depths anchored me. I could feel him absent mindedly stroking my hair. "Hold on we're almost there."

They pulled him away from me and the world went black.

***Criminal Minds***

"She shouldn't be alive." A female voice said. "She was stabbed at least fifty-eight times, both lungs were punctured multiple times, her pericardial sack was punctured as well, and she lost three and a half pints of blood. Not to mention that defensive wounds on her hands and arms."

"Fifty-eight times?" **He** asked. _What was his name again?_

"Yes, she's a fighter though. I'm surprised we didn't lose her on the table; her heart didn't stop, not even once. We were able to repair most of the damage." She said. "Do we know who she is yet?"

"According to the car registration and driver's license, her name is Mercedes Lynn Reid. She's a student at Harvard and her only emergency contact is her twin brother, Spencer, who's in Connecticut at Yale." Another male voice said. "They're seventeen."

"A seventeen year old survived this?" The female voice asked.

"Mercy." **He** said, his voice soft. He sounded closer this time.

"What was that, Hotch?" the other man asked. _Hotch? Hotchner. Aaron Hotchner, that's his name._

"She said her name was Mercy." Hotchner said.

"A shortening of Mercedes probably." The other man said. I heard footsteps. _No, don't go._

"H-Hotch…..ner." I called out, my voice sounded ruff and weak. A large hand closed gently around my small bandaged one. I heard the click of heels.

"She's awake?" the female voice said.

"Mercy?" He asked from next to me. I fought for a few minutes to get my eyes open. He smiled sadly down at me. "How are you feeling?" The woman was apparently a doctor, as she started checking my vitals.

"Tired." I said. He was stroking my hair again, it was quite soothing.

"We'll let you rest." He said and started to move away.

"Wait." I said, he stopped and looked at me. "It…. Was …. Him…. Wasn't… it?" I had to breathe between words. "The… reaper?" Hotchner hesitated. "Tell… me."

"It appears that way." He said reluctantly.

"Thought… so." I said.

"She really needs to rest." The doctor said.

"No… need … to … tell … them… what …. I … remember…" I said.

"How much do you remember?" the other man asked. I turned to look at him, he was older and a little shorter than Hotchner.

"Mercy, this is my partner Agent Gideon." Hotchner said. "It's all right you tell us." Gideon gave him an odd look. "How much do you remember?" He repeated his partner's question.

"All… of… it." I said. Hotchner closed his eyes and a pain look crossed his face. I squeezed his hand lightly. "He… was… about… six…foot… tall… and… wore… a… mask…. He… had… a… Boston… accent." Hotchner's eyes shot open.

"He spoke to you?" Hotchner asked, his voice a mixture of anger and surprise.

"Called… me… a… bitch… after… I… hit… him… with… a… book." I said, and then started coughing.

"Easy." Hotchner said.

"I have to insist that you stop now." The doctor said. I caught my breath enough to speak again.

"Wait…" I said and the doctor sighed. "The… stabbing… it's… sexual… he's… most… likely… impotent…" Hotchner gave me a confused look.

"How do you know that?" He asked.

"She has a PhD in Behavioral and Social Neuroscience from Caltech." Spencer's voice came from behind Agent Gideon. Both agents and the doctor turned to stare at him.

"Spencer." I said. He moved around Gideon and came to my side. He put his hand over mine.

"Oh, Mercy." He said, his eyes shining with unshed tears.

"I'm… okay… Spence." I said. He looked up at Hotchner.

"I'm Dr. Spencer Reid, Mercy's brother." He said.

"Aaron Hotchner, I'm with the FBI's Behavioral Analysis Unit." Hotchner said and pulled his hand away from my hair and extended it over me for Spencer to shake. Spencer shook his hand. "And this is my partner, Jason Gideon." He gestured at Gideon, before he started stroking my hair again. _He has no idea he's doing it._

"We spoke on the phone." Gideon said, stepping farther into the room to shake Spencer's hand as well.

"Yes, thank you for the call." Spencer said.

"Dr. Wells." The doctor introduced herself. They all stared at Hotchner's hand in my hair. He looked down and blushed.

"Sorry." He said pulling his hand away. I frowned a little.

"You're… fine…" I said. My eyelids started to feel heavy. "Very… sleepy… now."

"We'll let you rest now." Hotchner said. And I was out.


	4. Reid Babble and What the?

A/N: This chapter has a little bit of twin weirdness that is necessary for later chapters. It will relate to Spencer's drug use and it's affect on Mercy. Sorry if it's a bit too out there for some people. P.S. I also know a set of twins this actually happens to.

***3rd Person POV***

Spencer looked worriedly down at his sister as she fell into a deep sleep. She was very pale, covered in bandages, and had IV tubes coming from her arm. She was also receiving a transfusion. "What type of blood are you giving her?" He asked the doctor.

"Since we didn't know her blood type we're giving her O negative." The doctor said. "Do you know her blood type?"

"We're AB negative." Spencer replied.

"That's a pretty rare blood type, isn't it?" Hotchner piped up from the other side of the hospital bed. Spencer looked up at him with a confused expression.

"Why are you still here?" Spencer asked. Gideon had already wandered off. Hotch held up his hand, Mercy's hand was still tightly wrapped around it. Spencer shook his head. "Hope you don't need to go somewhere any time soon." Hotch smiled fondly.

"I thought so." Hotch said. Spencer turned back to the doctor.

"I can give blood if she needs more." He told her. The doctor nodded and he sunk into the chair by the bed.

"That would probably be best. A relative's blood is always preferred." She said. Then she looked at Hotch. "I have no objections to you staying, if you let her rest. But the decision is ultimately Spencer's." She turned back to Spencer. "I'll be back in a couple of hours to check on your sister." With that she turned and left. Hotch pulled the chair from by the foot of the bed over so he could sit.

The men fell into a comfortable silence, both worriedly watching the unconscious girl on the bed between them. A while later Spencer broke the silence. "I've never seen her sleep so deeply before." He said.

"Her body needs the rest in order to heal." Hotch said. "She's been through more than most people can handle." Spencer nodded and they lapsed into silence again. Then Hotch thought of something. "Do you mind if I ask you a question?"

"Go ahead." Spencer said.

"Where are your parents?" Hotch asked. "You're both only seventeen and your sister nearly died tonight. Most parents would be here." Spencer sighed and rubbed his temples.

"Our father left seven years ago and we haven't seen or heard from him since. Besides, I highly doubt he'd care even if I was able to contact him." Spencer said. "He and Mercy always hated each other."

"Why's that?" Hotch asked.

"Besides from having an IQ of 197, Mercy has a brain condition called Synesthesia." Spencer said. "The sensory part of her brain is enlarged. The symptoms include heightened senses and a sort of crossing of senses. She sees colors when she hears sounds, different pitches are different colors. She says everyone's voice is a different color."

"Wow." Hotch said.

"Yeah, he wanted to **fix** her. Needless to say, that didn't go over well with us or our mom." Spencer said. "Even the doctor that diagnosed Mercy was pretty pissed at him."

"And your mother?" Hotch asked.

"Huh?" Spencer asked. "What about our mother?"

"Where is she?" Hotch asked.

"Oh, she's in Nevada." Spencer said. "She's not well and she hates planes, but she'd come out here for Mercy. I, uh, haven't told her yet." He smiled sheepishly.

"If she's not well that's probably best." Hotch said.

"Yeah, Mercy would probably be more concerned about Mom than herself." Spencer said. "Knowing her, she already more concerned about how this is affecting me than her own injuries. That's just who she is." A young nurse popped her head in.

"I need to check Miss Reid's vitals." She said.

"It's Doctor." Hotch and Spencer corrected at the same time. The nurse looked at the chart in her hand and frowned.

"Her chart says she's seventeen." She said sounding confused.

"She is and she also has an IQ of 197." Hotch said angrily. "Do your job and go." The nurse scurried to check Mercy's vitals, scribbled them down on the chart, and scurried back out.

Spencer raised an eyebrow at Hotch, but said nothing. Hotch caught the look. "Sorry, that was unprofessional of me." Hotch said.

"No, you're fine." Spencer said and pushed up his sleeves. There were bruises on his arms in the same places the cuts on Mercy's arms were.

"What the…?" Hotch asked

"Crap." Spencer said and pulled his sleeves back down quickly.

"Those are in the-" Hotch started.

"Yeah, that happens sometimes." Spencer cut him off. "We've kind of kept it a secret."

"I understand." Hotch said and left it alone from there. The fell silent again.

"Do you have any idea who did this to her?" Spencer asked after awhile.

"Yes. A serial killer who calls himself the Reaper." Hotch said. "He normally calls 911 after he kills the victims, but Mercy managed to call right before she was attacked. She's the first to survive."

"Serial killers almost always have a distinct pattern or ritual." Spencer said. "Mercy disrupted his, he won't like it." Hotch raised an eyebrow.

"You take Behavioral and Social Neuroscience too?" Hotch asked.

"No, I'm currently working on a PhD in Psychology. Mercy is as well." Spencer said. "The only PhD we both currently have in common is Engineering. I have a PhD in Mathematics. Mercy hates math, it's one of the few things she's not good at. Well, it's not so much that she's bad at it but that she never paid attention long enough to get good at it. She says it's boring." Hotch smiled listening to the kid babble.

"You do that a lot, don't you?" Hotch asked.

"Huh?" Spencer asked and Hotch grinned.

"Never mind." He said. Mercy's eyes started fluttering again.


	5. Easy Sweetheart

***Mercy's POV***

I could hear Spencer talking animatedly about me. "Mercy hates math, it's one of the few things she's not good at. Well, it's not so much that she's bad at it but that she never paid attention long enough to get good at it. She says it's boring." He said.

"You do that a lot, don't you?" Hotchner asked, I could tell he was smiling. _He's still here?_

"Huh?" Spencer asked; he never tracts other people's part of the conversation well when he babbles.

"Never mind." Hotchner said. I started trying to open my eyes again, my eye lids fluttered for a moment. "Mercy?"Hotchner said. _He must have been watching me._ My eyes opened and I blinked a few times, my vision was a bit blurry.

"Hotchner….. Spencer?" I asked, I still had to pause between words to breathe.

"We're right here. I'll go get the doctor, okay." Spencer said and squeezed my hand lightly before jogging out of the room.

"How are you feeling?" Hotchner asked. I turned my head to look at him; he was staring at me with a very concerned look on his face. I smiled softly at him.

"Little… groggy… and… it still… hurts to… breath." I said. Then frowned and blinked a few times again, my vision was still blurry. "Everything's… blurry…what are… they…giving… me?" I shook my head, I didn't like this.

"Easy sweetheart, you're alright. You're safe." He assured me, hand in my hair again it was strangely soothing. I focused on his hand and tried to breathe slowly. "That's it. It's probably the anesthesia; we'll ask the doctor when she gets here."

"I can't… concentrate… I don't… like it." I said, shaking my head again.

"Shh, it's okay. I've got you sweetheart." He said softly. "We'll figure it out and fix it, okay?"

"Okay. … I trust you." I said. He smiled and his face softened, his eyes full of an emotion I couldn't identify through the blurriness.

Author's Note: Sorry for the wait and the short chapter. My health isn't the greatest and sometimes I don't get to writing for a while. I will update again as soon as I can.


End file.
